Fuel Economy and Air Conditioning

[petrified.rabbit]

its the pressure switch.

[RiderOnTheStorm]

So I bought a ScanGauge shortly after starting this thread and then drove about ~2000 miles in that time. With all of that said I have been carefully eyeing my "instantaneous" mpg and when I cycle the A/C on I lose about ~3 mpg. Typically this is at highway speeds (usually 65), but it goes from 33.5 to 30 or so. I think this supports what petrified was saying about a 10% performance decrease. Anyone else seeing anything similar?

[dragonwarrior2016]

That is not the case I have a 2006 Aveo Automatic transmission that Gets poor gas mileage when using Air conditioner Especially during A paper route the car only gets 24MPG My mom's new car gets way better than the Aveo.

[petrified.rabbit]

running a paper route is worse than city driving.

if your getting 24 mpg while doing something worse than city, with the ac on, your doing well..

[barbarianbug]

i usually use my air conditioner, but ive been averaging about 17 mpg. I dont know what's wrong, but i guess ill be rolling the windows down from now on.

[MetroMPG]

Just FYI:

From the U.S. National Renewable Energy Laboratory:

Vehicle air conditioning (A/C) systems represent the major auxiliary load on the engines of light-duty passenger vehicles, sport-utility vehicles (SUV), and heavy-duty vehicles and have a dramatic effect on fuel consumption and exhaust emissions in conventional vehicles and hybrid electric vehicles (HEV).

Recent studies (paper is from about 2000) have shown that, during the SC03 drive cycle (simulating city / ex-urban driving average speed of 21.6 miles/h, maximum speed 54.8 miles/h), the average impact of the A/C system over a range of light-duty vehicles was to increase

1) fuel consumption by 28%,
2) carbon monoxide emissions by 71%,
3) nitrogen oxide emissions by 81%, and
4) non-methane hydrocarbons by 30%.

Recent tests on hybrid electric vehicles (i.e., Toyota Prius / Honda Insight) at NREL [2] have shown that HEV fuel economy decreases by 30%-35% when the A/C operates.

[Jayman1967]

I own a 2005 and a 2008 Aveo 5-speeds both have well over 100,000 miles and both average between 42 and 48 mpg at 70 mph on the highway, but I don't have A/C in them. For some reason they don't start getting really good milleage till they hit 60,000 miles on the odmeter which both of mine did. One thing that is strange, the Aveo get better mileage at 70 mph then 55.
They only thing different is I run the Amsoil oil and oil filter on them since I drive close to 800 miles week and you can go 15,000 on oil change with Amsoil.

[gonecg]

A/C and mileage concerns.
I have over 127K on my 2005 Aveo with automatic and it still runs pretty well. I keep meticulous records on ALL my cars. I have gotten as low as 25.2 mpg around town with AC on to 29.6 mpg as the high. Our temps here has been 99 to 112 degrees this last six weeks so I run the AC a lot. My road mileage has been 32.1 to 38.3. I drive on the roads, no interstate, @ 60 to 65 mph. If I would drive 55 to 60 maybe I would get near 40mph. I do feel that the AC might take off some mpg, maybe 2 ? Very happy with my MPG

[Chevy Customer Svc]

A/C and mileage concerns.
I have over 127K on my 2005 Aveo with automatic and it still runs pretty well. I keep meticulous records on ALL my cars. I have gotten as low as 25.2 mpg around town with AC on to 29.6 mpg as the high. Our temps here has been 99 to 112 degrees this last six weeks so I run the AC a lot. My road mileage has been 32.1 to 38.3. I drive on the roads, no interstate, @ 60 to 65 mph. If I would drive 55 to 60 maybe I would get near 40mph. I do feel that the AC might take off some mpg, maybe 2 ? Very happy with my MPG

Hi cameraguy,

Thank you for your post. Glad to hear you're still reaping the benefits of great MPG with your Aveo at its current mileage and Aveo still is giving you good service. If you have any further questions or concerns, please post.

Vanessa
GM Customer Service